Evaluation of the usefulness of non-weight-bearing tunnel view using X-ray in the short term after medial meniscus posterior root tear onset: a retrospective study.

BACKGROUND: This study aimed to examine whether the non-weight-bearing tunnel view X-ray is effective for short-term evaluation of medial meniscus posterior root tear (MMPRT) by assessing the X-ray characteristics at the initial and follow-up visits. METHODS: This was a retrospective longitudinal study of 26 enrolled knees diagnosed with MMPRT on magnetic resonance imaging. The distance between the medial tibial eminence and medial femoral condyle (MTE-MFC distance) and medial tibiofemoral joint (MTFJ) width were measured by obtaining non-weight-bearing tunnel view and frontal view X-ray radiographs. The initial and follow-up values at a median interval of 17 days were compared. Additionally, the correlations between the MTE-MFC distance increase rate and body mass index (BMI), age, femorotibial angle (FTA), and posterior tibial slope (PTS) were evaluated using linear regression analysis. RESULTS: The tunnel view images of the initial and follow-up X-rays showed a significant increase in the MTE-MFC distance and a significant decrease in the MTFJ width. Furthermore, a moderate correlation was observed between the change in the MTE-MFC distance and the time interval between X-rays. However, no substantial correlation was observed for the change in the MTFJ width over time. Moreover, no significant correlation was observed between the change in the MTE-MFC distance in the non-weight-bearing tunnel view and BMI, age, FTA, and PTS. CONCLUSIONS: The non-weight-bearing tunnel view is highly beneficial for evaluating MMPRT progression in the short term.

Type V Tibial Tubercle Avulsion Fracture with Suspected Complication of Anterior Cruciate Ligament Injury: A Case Report.

Background and Objectives: Type V tibial tubercle avulsion fractures are extremely rare; therefore, information on them remains limited. Furthermore, although these fractures are intra-articular, to the best of our knowledge, there are no reports on their assessment via magnetic resonance imaging (MRI) or arthroscopy. Accordingly, this is the first report to describe the case of a patient undergoing detailed evaluation via MRI and arthroscopy. Case Presentation: A 13-year-old male adolescent athlete jumped while playing basketball, experienced discomfort and pain at the front of his knee, and fell down. He was transported to the emergency room by ambulance after he was unable to walk. The radiographic examination revealed a Type Ⅴ tibial tubercle avulsion fracture that was displaced. In addition, an MRI scan revealed a fracture line extending to the attachment of the anterior cruciate ligament (ACL); moreover, high MRI intensity and swelling due to ACL were observed, suggesting an ACL injury. On day 4 of the injury, open reduction and internal fixation were performed. Furthermore, 4 months after surgery, bone fusion was confirmed, and metal removal was performed. Simultaneously, an MRI scan obtained at the time of injury revealed findings suggestive of ACL injury; therefore, an arthroscopy was performed. Notably, no parenchymal ACL injury was observed, and the meniscus was intact. The patient returned to sports 6 months postoperatively. Conclusion: Type V tibial tubercle avulsion fractures are known to be extremely rare. Based on our report, we suggest that MRI should be performed without hesitation if intra-articular injury is suspected.

Output characteristics of Pr:YAlO3 and Pr:YAG lasers pumped by high-power GaN laser diodes.

We investigated whether Pr:YAlO3 and Pr:Y3Al5O12 (YAG) can work as gain media for high-power visible lasers and replace trivalent praseodymium (Pr)-doped fluoride crystals, with particular focus on thermal loading resistivity. Pr:YAlO3 exhibits a high laser gain at 747 nm, and we obtained a maximum output power of 1.2 W and a slope efficiency of 26.7% with high-power GaN laser diode pumping. Excited state absorption and large phonon energy hinder laser oscillation of Pr:YAG at room temperature. We obtained 616 nm laser oscillation of Pr:YAG at 40 K. Furthermore, we achieved a visible laser with Pr:YAG ceramics for the first time. The maximum output power is ∼30mW with a slope efficiency of ∼0.7%.

640-nm Pr:YLF regenerative amplifier seeded by gain-switched laser diode pulses.

We demonstrated the regenerative amplification of picosecond laser pulses generated by a gain-switched laser diode at 640 nm with a Pr:YLF crystal that was continuously pumped by a multimode blue laser diode. A 0.7-pJ seed pulse energy sufficiently suppressed the self-oscillation in the amplifier. The amplified pulse energy reached 33 µJ at a repetition rate of 10 kHz. The spatial beam quality was nearly TEM00. We also demonstrated second- and third-harmonic generation and obtained 320- and 213-nm pulse energies of 18 and 0.83 µJ at 10 kHz.

Intracavity second-harmonic pulse generation at 261 and 320 nm with a Pr3+:YLF laser Q-switched by a Co2+:MgAl2O4 spinel saturable absorber.

We demonstrated the power scaling of a passively Q-switched Pr3+:LiYF4 (YLF) laser at 523, 607, and 640 nm with a Co2+:MgAl2O4 (MALO) saturable absorber and analyzed the experimental results with a numerical simulation based on rate equations. A maximum pulse energy of 33.5 µJ was obtained with a pulse width of 30.9 ns and a repetition rate of 64.0 kHz at 640 nm. We demonstrated ultraviolet pulse generation at 261 and 320 nm by intracavity frequency doubling and obtained 63.3-ns pulses with a pulse energy of 7.0 µJ and a repetition rate of 64.6 kHz at 320 nm as well as 356-ns 261-nm pulses with a pulse energy of 0.2 µJ at a repetition rate of 82.0 kHz. To the best of our knowledge, a 261-nm pulse is the shortest wavelength laser directly generated from the intracavity second-harmonic generation of passively Q-switched lasers.

Diode-pumped 640 nm Pr:YLF regenerative laser pulse amplifier.

We demonstrated regenerative laser pulse amplification at 640 nm for the first time, to the best of our knowledge, with a mode-locked Pr3+-doped LiYF4 (Pr3+:YLF) oscillator as a picosecond seed pulse. A regenerative amplifier with a Pr3+:YLF crystal was continuously pumped by a multimode InGaN diode laser. At an absorbed pump power of 3.1 W, we obtained amplified pulse energy of 13 µJ at 10 kHz with an excellent spatial beam quality of M2∼1.1, demonstrated second-harmonic generation, and obtained a 320 nm pulse energy of 5.9 µJ.

High-power visibly emitting Pr3+:YLF laser end pumped by single-emitter or fiber-coupled GaN blue laser diodes.

We demonstrate the high-power continuous-wave operation of a Pr3+:YLF laser end pumped by blue laser diodes. As the pump source, we used four 5 W single-emitter blue laser diodes and a >20 W fiber-coupled module. In single-emitter-diode pumping, we obtained pump-limited output powers of 6.7 and 3.7 W at 640 and 607 nm, respectively. We successfully suppressed thermal aberration and obtained an output power of 3.4 W at a slope efficiency of 25% at 640 nm with good beam quality in the fiber-coupled module pumping.

Usefulness of a recanalized umbilical vein for vascular reconstruction in pediatric hepatic surgery.

PURPOSE: Pediatric surgeons currently engage in various abdominal vascular surgeries, which sometimes require vascular conduits or grafts. Herein, we report our experience with patients undergoing vascular reconstruction using a recanalized umbilical vein (rUV) and their long-term outcome. METHOD: Five patients with extrahepatic portal vein obstruction (EHPVO) underwent mesenterico-/porto-left portal vein (PV) bypass surgery using a short rUV conduit with an interposition vein graft. A sixth neonate with a huge hepatic tumor underwent PV reconstruction with anastomosis of rUV to the proximal PV stump following right hepatectomy with partial PV resection. A seventh patient underwent living donor liver transplantation for recurrent hepatoblastoma. The hepatic inferior vena cava (IVC) was resected because of tumor involvement and reconstructed by transposition of the infrahepatic IVC and interposition of rUV obtained from the donor liver graft. RESULTS: Sufficient flow through rUV was achieved and maintained in all patients without any complications during follow-up (0.7-6.9 years). Esophageal varices, splenomegaly, and other laboratory test abnormalities because of portal hypertension disappeared after surgery in patients with EHPVO. CONCLUSION: Our experience confirmed the usefulness and long-term patency of rUV as an entry to the intrahepatic PV and as a free vascular graft to reconstruct PV or IVC.

Comparison of Abdominal Drainage and No-drainage after Elective Hepatectomy: A Randomized Study.

BACKGROUND/AIMS: Recent clinical trials suggested that abdominal drainage is not needed in all cases and should be restricted in patients with chronic liver disease or patients who underwent minor liver resection. In this study we conducted a randomized study to determine whether abdominal drainage is beneficial or rather hazardous after hepatic resection. METHODOLOGY: Two hundred consecutive patients undergoing elective hepatectomy were entered for this prospective, randomized, case-controlled study. Liver resection was performed under intermittent Pringle maneuver. Clinical data such as postoperative complications and mortality rates were evaluated as well as intraoperative parameters. RESULTS: There were no significant differences in postoperative morbidity between with and without abdominal drainage groups 16 vs. 12%). However, complications directly related no drainage such as drain site bleeding and infection, abdominal abscess, bile fistula, and ascites (CDRD) tended to be higher in the drainage group than the no-drainage group (9 vs. 3%, p = 0.067). Particularly, there was high incidence of CDRD in the drainage group compared with the no drainage group in patients with chronic liver diseases (13.2 vs. 1.8%, p = 0.027). CONCLUSIONS: We do not recommend systematic drainage after elective hepatectomy, irrespective of the extent of resection and of the underlying liver diseases when the surgical procedure has been satisfactory.

One Hundred Hepatectomies without Hospital Death under Intermittent Hepatic Inflow Clamping for 30 Minute Duration.

BACKGROUND/AIMS: Temporary clamping of the hepatic inflow is routinely applied to minimize haemorrhage during liver parenchyma. In this report, we describe successful intermittent application of the hepatic inflow for 30 minutes with zero hospital death in consecutive 100 hepatectomies. METHODOLOGY: One hundred consecutive patients undergoing elective liver resection were entered for this prospective study. A synthetic protease inhibitor (gabaxate mesilate, GM) was intravenously administrated continuously starting 12 hours before the operation until the second postoperative day. The patients underwent hepatectomy with a cycle consisting of intermittent application of inflow clamping for 30 minutes, followed by 5 minutes of declamping. Intraoprative data were evaluated together with complications and hospital death rates. Liver function tests were performed on postoperative days, 1, 3 and 7. RESULTS: All the patients discharged the hospital with a zero motality and an average hospital stay of 8 days postoperatively. Peak for aminotransferase were observed postoperative day 1 (382 ± 268, 245 ± 204 IU/L, mean ± SD for serum S-AST and S-ALT). The bilirubin and prothrombin times were normalized day 7 postsurgery. There were no differences between GM protocols. CONCLUSIONS: We have successfully confirmed that a cycle consisting of intermittent application of the hepatic inflow clamping yields safe hepatectomy under effective control of bleeding, when combined with use of a protease inhibitor.

Medial Meniscus Posterior Root Reconstruction and Open-Wedge High-Tibial Osteotomy for Medial Meniscus Posterior Root Tear With Varus Knee Alignment: A Retrospective Study on Short-Term Outcomes.

PURPOSE: We describe 13 cases of medial meniscus posterior root tear (MMPRT) with varus knee alignment treated with medial meniscus posterior root reconstruction (MMPR-R) and open-wedge high-tibial osteotomy (OWHTO) to identify an optimal MMPRT treatment. METHODS: We retrospectively reviewed 13 patients (mean age: 66.3 ± 8.0 years) who underwent MMPR-R and OWHTO. The Knee Injury and Osteoarthritis Outcome Score (KOOS), femorotibial angle (FTA), percentage mechanical axis (%MA) on radiography, and medial meniscus extrusion (MME) on magnetic resonance imaging (MRI) between the preoperative period and last follow-up were compared. Moreover, meniscus healing status and the International Cartilage Repair Society (ICRS) classification of the medial femoral condyle and medial tibial plateau on arthroscopy between the initial surgery and second-look arthroscopy were compared. RESULTS: The mean follow-up duration was 12.8 ± 2.2 months. At the last follow-up, the KOOS significantly improved (P < 0.01). Based on the FTA and %MA, the varus alignment was predominantly corrected at the last follow-up (P < 0.01). The MME was increased in nine (62.9%) patients, and the mean MME significantly increased at the last follow-up (P = 0.04). Second-look arthroscopy revealed improvements in the ICRS grade for the medial femoral condyle and medial tibial plateau in six (46.2%) patients. However, the results did not significantly differ. Regarding meniscus healing, four (30.8%) patients presented with complete healing, eight (57.1%) with partial healing, and one (7.7%) with failed healing. CONCLUSIONS: The MMPRT with varus knee alignment significantly improved with MMPR-R and OWHTO. However, the MME and meniscus healing were unsatisfactory.

Human parvovirus B19-induced acute glomerulonephritis: a case report.

Human parvovirus B19 (HPV B19) infection is well known as a cause of erythema infectiosum in children. Acute glomerulonephritis due to HPVB19 infection is rarely observed in adults. Here, we present the case of a 45-year-old female who showed acute glomerulonephritis induced by HPVB19 infection with various autoantibodies. She had proteinuria (175 mg/g creatinine) and hematuria (20-29 erythrocytes per high-power field) in a urinalysis, and various autoantibodies such as antinuclear antibodies, proteinase-3-antineutrophil cytoplasmic antibodies (PR3-ANCA), antiglomerular basement membrane (GBM) antibodies, and anticardiolipin antibodies in a blood examination. A renal biopsy showed that endocapillary proliferative glomerulonephritis comprised of mononuclear cell infiltration. By using immunofluorescence microscopy, IgG, IgA, IgM, C3, C4, and C1q deposits were detected mainly in glomerular capillaries. Electron-dense deposits were detected in the subendothelial area and mesangial area by using electron microscopy. All symptoms and abnormal laboratory data were self-improved. Our patient's case may provide a clue to the etiology of ANCA-associated vasculitis or lupus nephritis.

Osteosynthesis with Arthroscopy of a Nonunited Tibial Anterior Cruciate Ligament Avulsion Fracture 30 Years after Injury.

There are a few reports on the treatment of nonunited tibial anterior cruciate ligament (ACL) avulsion fractures. To our knowledge, this is the first report of a case of nonunited tibial ACL avulsion fracture 30 years after injury. A 36-year-old woman injured her knee during a road traffic accident 30 years ago. Since then, she had persistent knee instability that was left untreated. She presented to our clinic because of knee pain she had been experiencing for a week. Radiography and computed tomography revealed tibial ACL avulsion fracture nonunions. Screw fixation with arthroscopy was performed, and bone fusion was obtained. The knee injury and osteoarthritis outcome score improved from 24 points preoperatively to 83 points postoperatively. The nonunion of intercondylar eminence fractures of the tibia, even up to 30 years after the initial injury, can be treated by osteosynthesis with arthroscopy.

A case of focal segmental glomerulosclerosis with myeloid bodies.

The presence of myeloid bodies in electron microscopy is a characteristic finding of Fabry's disease. Here, we present a male patient, whose renal biopsy findings suggested the coexistence of focal segmental glomerulosclerosis and Fabry's disease, because of the presence of segmental hyalinosis and/or sclerosis in glomeruli and myeloid bodies in electron microscopy. But finally, Fabry's disease was excluded as a diagnosis because the α-galactosidase A activity in leukocyte and plasma in this patient was within normal limits. After renal biopsy, although he received medication including steroid therapy, his renal function gradually decreased to end-stage renal failure and hemodialysis was initiated. Until now, he does not exhibit any specific symptoms. In conclusion, our case suggests that occasional myeloid bodies in renal biopsy specimens should be interpreted with caution.

Medial Meniscus Posterior Root Reconstruction and Open- Wedge High Tibial Osteotomy for Medial Meniscus Posterior Root Tear with Varus Knee: A Case Report.

Introduction: Pull-out suture, suture anchor, and open- wedge high tibial osteotomy have been widely used for surgical treatment of medial meniscus posterior root tear, and relatively good clinical results have been reported. However, radiologic and arthroscopic findings are not sufficient. This report describes the first case, to the best of our knowledge, of medial meniscus posterior root reconstruction and high tibial osteotomy for medial meniscus posterior root tear with varus knee. Case Report: A 78-year-old Japanese man was referred to our hospital due to the right popliteal pain. Plain radiography showed the mechanical axis percentage of the right limb to be 17%, indicating a varus mechanical axis. magnetic Magnetic resonance imaging noted a medial meniscus posterior root tear. Medial meniscus posterior root reconstruction and high tibial osteotomy were performed. His knee injury and osteoarthritis score improved from 22 points preoperatively to 91 points 1 year postoperatively. The graft had a good live induction and the medial meniscus hoop was maintained. Conclusion: This report is the first case, to the best of our knowledge, of medial meniscus posterior root reconstruction and high tibial osteotomy for medial meniscus posterior root tear with varus knee. This type surgical technique may be useful for a meniscus posterior root tear with varus knee.

Localized Pigmented Villonodular Synovitis of the Bilateral Knee: A Case Report.

Introduction: Localized pigmented villonodular synovitis (PVNS) is a rare and benign condition of synovial tissue proliferation that affects the joints, tendon sheaths, and bursae. This case report is the first to describe a patient with a diagnosis of localized PVNS of the knee after presentation with bilateral and simultaneous onset of associated knee pain. Case Report: A 28-year-old Japanese woman presented to our hospital with a 1-year history of bilateral knee pain and right knee locking that started 1 month ago. Magnetic resonance imaging demonstrated a mass lesion in both the anterior compartment of the right knee and in the posterior compartments of the left knee. Arthroscopic resection of the lesions was performed, and the diagnosis of localized PVNS was made by pathological analysis. At the 6-month follow-up, no evidence of recurrence was noted. Conclusion: This case report describes localized PVNS of the bilateral knee, which is extremely rare. PVNS is a disease requiring surgical resection and should not be overlooked. It should be treated with the possibility of bilateral occurrence in mind.

Arthroscopic Osteophyte Resection for Osteophyte-Induced Popliteal Impingement.

Popliteal tendinitis causes lateral knee pain. A cause is impingement of the popliteal tendon by lateral femoral condylar osteophytes. Conservative and surgical treatments have been reported; however, popliteal impingement is a relatively rare disease, and no treatment has been established. Reduction of mechanical stress is important in the treatment of impingement syndromes. The popliteal tendon is an important tissue that contributes to knee stability and, therefore, usually cannot be transected. On the other hand, osteophyte resection may allow the reduction of mechanical stress. Therefore, we describe an arthroscopic osteophyte resection technique for the treatment of osteophyte-induced popliteal impingement. In brief, this technique involves confirmation of popliteal impingement, osteophyte resection using an osteotome, smoothening of the resected area, and confirmation of the resolution of popliteal impingement.

Arthroscopic Medial Meniscus Posterior Root Reconstruction and Pull-Out Repair Combined Technique for Root Tear of Medial Meniscus.

Repair of medial meniscus posterior root tear is important in preventing rapid progression of knee osteoarthritis. There are many repair techniques for medial meniscus posterior root tears, and good clinical results have been reported. Conversely, in terms of improving extrusion and healing meniscal injuries, sufficient results have not been obtained. Reconstruction of the medial meniscus posterior root can restore meniscal hoop action and normal knee biomechanics. Moreover, pull-out repair technique provides strong traction. We describe arthroscopic medial meniscus posterior root reconstruction and pull-out repair technique combined technique for medial meniscus root tear.

Potential of the non-weight-bearing tunnel view in diagnosing medial meniscus posterior root tear: a pilot study of X-ray characteristics.

PURPOSE: Early detection of medial meniscus posterior root tear (MMPRT) is important in preventing the rapid onset and progression of degenerative knee disease. Diagnosis is facilitated by the availability of non-weight-bearing X-ray view, but information on the X-ray characteristics of MMPRT is scarce. Here, we conducted a pilot study of the X-ray characteristics of MMPRT on non-weight-bearing tunnel view. METHODS: We retrospectively reviewed 43 consecutive patients treated in the outpatient department for medial knee pain or popliteal pain. Patients were divided into MMPRT (21 knees) and non-MMPRT groups (22 knees). We investigated X-ray characteristics and magnetic resonance imaging findings. Femorotibial angle, posterior tibial slope, medial tibial eminence (MTE)-medial femoral condyle (MFC) distance (contralateral and affected sides, and difference between the two), medial tibiofemoral joint (MTFJ) width (contralateral and affected sides, and difference between the two), and meniscus radial dislocation between the groups were evaluated using the Mann-Whitney U test. The association between X-ray characteristics and MMPRT was determined using univariate and multivariate logistic regression analyses. RESULTS: A highly significant difference between the affected and contralateral sides was seen in MTFJ width and MTE-MFC distance on non-weight-bearing tunnel view between the MMPRT and non-MMPRT groups. Moreover, a difference in MTFJ width of <-0.575 mm and in MTE-MFC distance of >0.665 mm between the affected and contralateral sides was useful in predicting MMPRT. CONCLUSIONS: The non-weight-bearing tunnel view is useful for the initial diagnosis of MMPRT. Prospective evaluation in a larger population is warranted.

Analysis of T-cell receptor usage in myeloperoxidase--antineutrophil cytoplasmic antibody-associated renal vasculitis.

BACKGROUND: Bacterial superantigens produced by Staphylococcus aureus may be associated with the onset of proteinase-3 antineutrophil cytoplasmic antibody (PR3-ANCA)-associated vasculitis, including Wegener's granulomatosis. We investigated T-cell subsets to assess the superantigens present in patients with myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis. METHODS: Peripheral-blood mononuclear cells (PBMC) obtained from 40 normal controls and ten patients with MPO-ANCA-associated vasculitis were stained with fluorescence-labeled monoclonal antibodies against T-cell markers, including 17 variable regions of T-cell receptor beta-chains (TCR-Vbeta) and were then analyzed using flow cytometry. RESULTS: Among PBMCs, the percentage of CD3(+) cells from patients with MPO-ANCA-associated vasculitis was significantly lower than that from normal controls, but there were no differences between the two groups in the percentage of CD19(+) cells or CD16(+) cells. Although there were no differences regarding the overall percentage of CD4(+) cells between the two groups, the percentage of CD4(+)CD45RO(+) cells in patients with MPO-ANCA-associated vasculitis was significantly higher than that in normal controls, and percentages of CD4(+)CD45RO(+)HLA-DR(+) and CD4(+)CD45RO(+)CD62L(low) cells in patients with MPO-ANCA-associated vasculitis were also significantly increased. There was no significant difference between the two groups in terms of the usage of the 17 different TCR-Vbeta regions. CONCLUSION: There was no difference in bacterial superantigens between controls and MPO-ANCA-associated vasculitis patients because of the absence of specific usage of TCR-Vbeta regions. Given the elevated levels of memory T cells, conventional antigens rather than superantigens may be associated with the pathogenesis of MPO-ANCA-associated vasculitis.